﻿/*
* Copyright 2010 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License")
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*     http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Ngilead.Test.Models;
using NHibernate;
using System.Collections;
using Ngilead.Test.Models.Stateless;

namespace Ngilead.Test.DAO
{
    /// <summary>
    /// Message data access class
    /// </summary>
    public class MessageDAO : GenericDAO<Message, Int64>, IMessageDAO
    {
        /// <summary>
        /// Load last message
        /// </summary>
        /// <returns>Message</returns>
        public Message LoadLastMessage()
        {
            Message result = null;
            ISession session = null;
            ITransaction transaction = null;

            try
            {
                session = GetSession();
                transaction = session.BeginTransaction();

                IQuery query = session.CreateQuery("FROM Message ORDER BY Date desc");
                query.SetMaxResults(1);

                result = query.UniqueResult<Message>();
                transaction.Commit();
            }
            catch (Exception ex)
            {
                transaction.Rollback();
                throw new Exception("Could not load last message", ex);
            }

            return result;
        }

        /// <summary>
        /// Load all messages
        /// </summary>
        /// <param name="startIndex">Start index</param>
        /// <param name="maxResult">Max result</param>
        /// <returns>Messages</returns>
        public IList<Message> LoadAllMessage(int startIndex, int maxResult)
        {
            IList<Message> result = null;
            ISession session = null;
            ITransaction transaction = null;

            try
            {
                session = GetSession();
                transaction = session.BeginTransaction();

                IQuery query = session.CreateQuery("FROM Message ORDER BY Date desc");
                query.SetFirstResult(startIndex);
                query.SetMaxResults(maxResult);

                result = query.List<Message>();
                transaction.Commit();
            }
            catch (Exception ex)
            {
                transaction.Rollback();
                throw new Exception(String.Format("Could not load all messages ({0}, {1})", startIndex, maxResult), ex);
            }

            return result;
        }

        /// <summary>
        /// Load detailed message 
        /// </summary>
        /// <param name="id">Id</param>
        /// <returns>Message</returns>
        public Message LoadDetailedMessage(Int64 id)
        {
            Message result = null;
            ISession session = null;
            ITransaction transaction = null;

            try
            {
                session = GetSession();
                transaction = session.BeginTransaction();

                StringBuilder hqlQuery = new StringBuilder("FROM Message message");
                hqlQuery.Append(" INNER JOIN FETCH message.Author");
                hqlQuery.Append(" LEFT JOIN FETCH message.Keywords");
                hqlQuery.Append(" WHERE message.Id = :id");

                IQuery query = session.CreateQuery(hqlQuery.ToString());
                query.SetInt64("id", id);

                result = query.UniqueResult<Message>();
                transaction.Commit();
            }
            catch (Exception ex)
            {
                transaction.Rollback();
                throw new Exception(String.Format("Could not load detailed message for id {0}", id), ex);
            }

            return result;
        }

        /// <summary>
        /// Lock message
        /// </summary>
        /// <param name="session">Session</param>
        /// <param name="message">Message</param>
        public void LockMessage(ISession session, Message message)
        {
            ITransaction transaction = null;

            try
            {
                transaction = session.BeginTransaction();

                if (message.Id > 0)
                    session.Lock(message, LockMode.Upgrade);
                transaction.Commit();
            }
            catch (Exception ex)
            {
                transaction.Rollback();
                throw new Exception(String.Format("Could not lock message for id {0}", message.Id), ex);
            }
        }
    }
}